A standard transcontainer for shipping produce, frozen food, or the like is basically an elongated parallepipedal box having a closed front end wall, a rear wall formed by a pair of doors, side walls, a top wall, and a floor. Most of the walls are formed as two metal sheets or skins sandwiching a mass of closed-cell insulation. The top skin of the floor is provided with a plurality of longitudinally extending T-section rails that define longitudinal passages or slots. With containers of the so-called porthole type a cooler is hooked up to circulate cold air through the passages in the floor, thereby passing this chilled air around the freight inside the container.
The problem with this type of container is that it is difficult to load and unload. Getting a fork lift through the open doors and into the container is difficult, entailing climbing over the edge of the floor rails. The upper edge of the door opening is frequently down somewhat, so that getting the freight under this obstacle while still lifting it up for the floor is difficult, limiting the height of the freight that can be loaded.